My son's betta Rock N Roll has been dealing with some sort of chronic swim bladder condition for the past several months. There is a long thread on here somewhere describing all the different courses of treatment he's been through and lately he has been on a maintenance dose of 1 tsp/g Epsom Salt with 2x weekly water changes (50% & 100%) - he is in a 2.5G heated (80 degrees) tank. For days now he has been lingering near the surface and not able to swim down for more than a few seconds without bobbing back to the surface and it is very typical that he will go through periods like this. Today, however, he is suddenly "normal" - swimming around all over the place, able to swim all the way down to the bottom of the tank (even resting there for a little while sometimes, which REALLY freaks me out!) I don't know why, but this sudden change in behavior is making me nervous. Even though it seems like he is acting "better" it is so different from the way he has been that I am wondering if it could be the start of something that is going wrong? He is eating normally and responsive to people interacting with him. I think I am just being paranoid, but seeing him laying at the bottom of the tank every so often just seems so unnatural after months of not being able to do that...I don't know what would account for this sudden change? Any thoughts? His last water change was 100% on Saturday so I don't think it is directly related to that...